Stylus pointing devices are utilized to input information and/or to control applications executing on a host electronic device. A stylus may be characterized as active or passive. An active stylus emits signals that are detected by the host device and processed to control an application. A passive stylus modifies an electrical property, such as the capacitance or resistance of a display surface or assembly of the host device. When the stylus tip is brought into close proximity to the display, the position thereof can be determined in several ways, such as, for example by: the effect of the stylus on the electrical properties of the display (i.e., by sensing electromagnetic induction, changes in electrical resistance, variance in electrical capacitance, and the like); changes in the optical properties of the tablet; processing ultrasonic/optical signals, etc.
In the instance of an active stylus that emits radio signals, a radio transmitter associated with the stylus generates and radiates an electromagnetic field that is sensed and processed by the host to yield a stylus position. The active stylus circuitry requires battery power, the output of which is limited by size constraints.
It would therefore be desirable to provide an expedient for extending battery life when the device is not in use, without requiring the user to take active steps to power down the stylus.